docs: def simple_fault_node(fault_trace, dip, upper_depth, lower_depth):
      """
      :param fault_trace: an object with an attribute .points
      :param dip: dip parameter
      :param upper_depth: upper seismogenic depth
      :param lower_depth: lower seismogenic depth
      :returns: a Node of kind simpleFaultGeometry
      """
      node = Node('simpleFaultGeometry')
      line = []
      for p in fault_trace.points:
          line.append(p.longitude)
          line.append(p.latitude)
      node.append(Node('gml:LineString', nodes=[Node('gml:posList', {}, line)]))
      node.append(Node('dip', {}, dip))
      node.append(Node('upperSeismoDepth', {}, upper_depth))
      node.append(Node('lowerSeismoDepth', {}, lower_depth))
      return node